int countWords(char **words1, int words1Size, char **words2, int words2Size)
{
    int count = 0;
    char t[256];
    int flag = 1, k = 0;
    for (int i = 0; i < words1Size; i++)
    {
        flag = 1;
        k = 0;
        strcpy(t, words1[i]);
        for (int j = 0; j < words1Size; j++)
        {
            if (strcmp(t, words1[j]) == 0 && i != j) // 判断words1[i]在words1中是否唯一
            {
                flag = 0;
                break;
            }
        }
        if (flag == 1)
        {
            for (int j = 0; j < words2Size; j++) // 判断words1[i]在words2中是否唯一
            {
                if (strcmp(t, words2[j]) == 0)
                    k++;
            }
        }
        if (k == 1)
            count++;
    }
    return count;
}